The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into the engine is regulated via a throttle valve, which adjusts a throttle area to control air flow into the engine. A fuel control system adjusts the rate that fuel is injected to provide a desired air/fuel mixture to the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.
In spark-ignition engines, spark initiates combustion of an air/fuel mixture provided to the cylinders. In compression-ignition engines, compression in the cylinders combusts the air/fuel mixture provided to the cylinders. Spark timing and air flow may be the primary mechanisms for adjusting the torque output of spark-ignition engines, while fuel flow may be the primary mechanism for adjusting the torque output of compression-ignition engines.
Exhaust gas passing through an exhaust system may include particulate matter. Exhaust components, such as particulate filters, have been developed to filter the particulate matter. These components, however, increase the cost and mass of a vehicle.
A system described in U.S. Pat. No. 8,989,989 (hereinafter “the '989 patent”), the description of which is incorporated herein in its entirety, describes a system that includes a temperature estimation module and a fuel control module. The temperature estimation module estimates a piston temperature associated with a cylinder based on engine operating conditions. The fuel control module controls an injection timing associated with the cylinder, an injection pressure associated with a cylinder, an injection location associated with a cylinder, or a number of injections per engine cycle associated with the cylinder based on the estimated piston temperature.